This type of combination lamp is known and sold, for example, under the trademark Duled® by Osram Sylvania. Combination lamps that provide both normal and reduced illumination are also disclosed in U.S. Pat. No. 6,400,104 (Ham), U.S. Pat. No. 7,246,919 (Porchia et al.), and U.S. Pat. No. 7,318,659 (Demarest et al.) These combination lamps provide an alternative to single purpose lamps and find use, for example, as a lamp for normal illumination that can also function as a low intensity night light.
Nevertheless, the known combination lamps can be improved by simplifying the change between reduced and full illumination. Known combination lamps switch between normal illumination and reduced illumination by cycling the input power switch. The user may be required to cycle power and wait a certain time before re-applying power to change the operating mode. This may be confusing to a casual user as the expected operating mode is not immediately forthcoming. In some instances, the user may have to wait in the dark for several seconds before re-applying power to change the operating mode, which can pose safety concerns. By way of further example, when the combination lamp is used on a child's nightstand, the child may have to get out of bed and walk to a wall switch to obtain the full illumination.
It is also desirable to provide some light when the lamp providing full illumination fails. LEDs last significantly longer than compact fluorescent lamps and having the LED remain ON when the compact fluorescent has failed would provide an important source of emergency light in certain applications.